1. Field of the Invention
The present disclosure relates to direct current-to-direct current (DC-DC) voltage converters, and more particularly to overvoltage protection for non-isolated (transformerless) DC-DC voltage converters.
2. Description of Related Art
For many years, aircraft electrical equipment incorporated a centralized power supply consisting of a multi-output, transformer isolated DC-DC converter to meet system load requirements. As processing systems have become more complex, requiring multiple low voltage rails with increased current capability and power sequencing, the power supply has trended towards a distributed power architecture. Generally, distributed power architectures include a single output, transformer isolated DC-DC converter with a distribution bus powering a series of point-of-load (POL) regulators. The POL regulators are generally efficient, provide tight regulation, reduced ripple and noise, and improved transient response while the transformer provides input/output ground isolation as well as fault isolation. In the event of a shorted switching element, the transformer typically isolates the input voltage to the converter from the output preventing fault propagation to the load. In systems not requiring input/output ground isolation, the transformer isolated DC-DC converter can be replaced with a non-isolated regulator to reduce cost, board area, and complexity. Certification requirements for such devices may include reducing the risk that a shorted pass element could cause the input voltage to be directly to the device output. The present disclosure provides a solution for this concern.